The ship is smaller than a car, flanked by two long solar panels. It is due to strike next fall, in about ten months, an asteroid the size of a football field (about 160 meters in diameter), which will then be located eleven million kilometers from Earth.
The asteroid is called Dimorphos and is in fact a moon, orbiting a larger asteroid, named him Didymos (780 meters in diameter).
To circle the large asteroid, Dimorphos currently takes 11 hours and 55 minutes. Scientists expect to reduce its orbit by about 10 minutes.
“It’s a very small change but it might be all we need to deflect an asteroid colliding with Earth, if we ever have to, provided we find this asteroid early enough.” , explained Tom Statler.
The exact effect that the impact will have is not known at the moment because it depends in particular on the composition of the asteroid.
It is this precise change in trajectory, which will then be measured using telescopes from Earth, that scientists want to determine. The results will be used in calculations to help define, in the future, how much mass must be projected against a given type of asteroid to cause sufficient deflection.
– Explosion –
Is Dimorphos made of solid or more porous rocks? Scientists know nothing about it, and the asteroid will not appear in images transmitted by the ship until just an hour before the collision. Its shape, round or oblong, will only be clear 2 minutes before.
Then the explosion, and radio silence.
The following images will come from a small satellite developed by the Italian Space Agency. It will be released by the main ship ten days before impact.
Three minutes after the collision, it will fly over Dimorphos, in order to observe the effect of the shock and, with a little luck, the crater on the surface.